Causes Of Crosstalk; An Ip Phone Rings But You Cannot Hear The Peer End When Picking Up The Ip Phone; An Ip Phone Cannot Obtain Time Information From The Ntp Server - Huawei espace 7810 Administrator's Manual

Huawei IP Phone eSpace
7810&7820&7830&7850&7870&7803X
Administrator Guide

4.2.6 Causes of Crosstalk

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4.2.7 An IP Phone Rings but You Cannot Hear the Peer End When
Picking Up the IP Phone
Symptom
An IP phone rings when receiving a call, but you cannot hear the peer end when picking up
the IP phone.
Cause
This fault occurs when signaling messages can be transmitted but media streams cannot be
transmitted. Signaling messages are transmitted by a server and media streams are transmitted
from end to end.
In the case of unidirectional communication on the IP Phone network, you can make a call on
a specified trunk circuit to locate the cause (upper-level office fault or internal office fault).
If no fault is found on all the trunk circuits, check the internal office fault. In the case of
unidirectional communication in the internal office, you can use the packet capture tool to
analyze whether the network setting is correct. The internal office fault may be the hardware
or software fault.
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Troubleshooting
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4.2.8 An IP Phone Cannot Obtain Time Information from the NTP
Server
Symptom
When a computer functions as the NTP server, the IP phone cannot obtain time information.
Issue 01 (2011-12-31)
The MAC address of the IP phone conflicts, which has a small possibility.
Sessions are not synchronized to the lower-level NAT and firewall when the SBC is
used.
Hardware faults can be often detected. A fault occurs in an office direction or a fault
often occurs. To locate a hardware fault, attempt to replace the hardware for testing, such
as switching the MCU and replacing the trunk board or terminal. The overall principle is
to trace the call where a fault occurs, make a summary of fault occurrence, eliminate
possible causes one by one, and locate the actual cause.
To locate a software fault, trace the call information when the fault occurs step by step
and describe the scenario and recurrence conditions. Then send the information to the
R&D personnel for further analysis.
Media streams cannot be transmitted.
The IP phone or headset is connected to an incorrect port. The headset ports of eSpace
7810, 7820, 7830, 7850 and 7870 use RJ-9 and the IP phone ports also adopt RJ-9.
If RTP encryption is enabled on an IP phone but encryption is disabled on the peer end,
unidirectional communication may occur. Verify that RTP encryption is enabled or
disabled both on the two ends.
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